I just got this at r775:
{'⍝'}
copying: '1' at Executable.cc:655
tidx: '1' at Executable.cc:655
----------------------------------------
-- Stack trace at Executable.cc:655
----------------------------------------
0x7f055ac095f0 __libc_start_main
0x444ae5 main
0x5804bd Workspace::immediate_execution(bool)
0x48a852 Command::process_line()
0x48a8df Command::do_APL_expression(UCS_string&)
0x499dbb StatementList::fix(UCS_string const&, char const*)
0x497b26 Executable::setup_lambdas()
0x497835 Executable::setup_one_lambda(long, int)
0x4970b9 Executable::extract_lambda_text(Fun_signature, int) const
========================================
-k
